Automatic telephone system



Sept-25, 192s.

L. L. RUGGLES AUTOMATiC mmarnom: srswn Original Filed June 6 1925 6 Sheets-Sheet 1 q) I\ V OFFICE A 1m L Banal-:1 L Rua les Sept. 25, 1928.

L. L. RUGGLES AUTOMATIC TELEPHONE sYs'raI 2 II I II I II I III mm BE in H H t u w nmmmmzar Tm Lennard LRu Sept. 25, 1928.

L ennard LRu L L. RUGGLES AUTOMATIC TELEPHONE, 3min Original Filed June 6, 1925 m fi Sept. 25, 1928.

L. L. RUGGLES wrom'rxc TELEPHONE svswm:

6 Sha na-Sheet 4 Original Filed June 6,.1925

I 1. mm in r u 0R 5 Md m h. n v I L 83 N8 an 6 Sheets-Sheet 5 Sept. 25, 192a L. L. RucGLls AUTOIATICV TELBPHQB.,M Original lned'June 6, ms

, LEaniPdLRU IE5 6 Shats-Shet 5 Sept. 25, 1928.

L. L. RUGGLES AUTOMATIC TELEPHONE sys'rflll Original Filed June 6, 1925 men ' Imam-s LeunardLRu Patented Sept. 25, 1928.

UNITED STATES PATENT OFFICE."

LEONARD L. RUGGLES, OF WHEATON, ILLINOIS. ASSIGNOR, BY MESNE ASSIGNIJENTS, TO AUTOMATIC ELECTRIC-INC, OF CHICAGO, ILLINOIS, A CORPORATION OF DELA- WARE.

' AUTOMATIC TELEPHONE SYSTEM.

Original applicationfllcd June 6, 1925, Serial No. 35,280. Divided and this application filed May 26,

This application is a division of my prior application Serial #235,280, filed June. 6, 1925.

The present invention relates to automatic telephone systems in general, but is concerned more particularly with automatic telephone systems in which directors are employed to translate the office digits of the telephone numbers into the codes necessary to effect the trunking of the various calls to the desired ottices by way of the most suitable paths; and the principal object is the provision of novel circuit arrangements whereby a record vill. be kept of the number of calls directed to a certain office. 7

The above statement of the main object of the invention, of course, sets that object torth only broadly, and for a clearer understanding of the s ope of the invention reference may be had to the outline of the system hereinafter given.

Referring now to the accompanying drawings, con'ipris ng Figs. 1-8, Figs. 1-6 show by means of the usual clrcuit diagrams a certain amount of apparatus employed in a telephone system embodying the principles of the inventionyFig. 7 shows five 10,000 line (ultimate capacity) otfices interconnected by trunk lines, and it purports to show the relative geographical positions of the officer;

. shown; and Fig. 8 is a trunking diagram showing how ca-llsoriginated in otlice A are completed in the other otiices shown in Fig. T.

It will be understood that the otlices shown in Fig. 7 may represent only a small partof a large inulti-oilice network.

It will be noted that there are two ways to trunk calls to the oftice I) from the office A, that is, calls may go from A to C and from C to D, or from A to B and .trom B to D. Calls from A to E go by way of C as may be seen. i

The outgoing trunk lines from A to C and from A to B are taken from the first selector bank as may be seen from Figs. 1 and 2. The

first selectors of which the selector S. Fig. 1, is typical are of the automatic Vertical type, that is, two levels can be combined in such a way that, when the lower level is busy the wipers are automatically raised to the upper level and are then i'otatedto find an idle trunk Serial No. 194,250.

in that level. The calls from A to D are normally trunked by way of C, but when the trunks to C become busy the calls are automatically sent to B and then'when the next digit is transmitted the seized selector in B extends the call over to D ust as though a selector in C had been seized, the trunks to C coming from the same selector'leyel in both ofiices. 011 calls from A to C and from A to E, however, the situation is not the same because the call is not automatically trunked to the destination by merely permitting the selector S, Fig. 1, to raise its wipers to the next higher level. Two methods of handling thecalls destined for C and E from A, when the trunks from A to Care busy, are availa )lG. r

In case the trunk group from B to C is a small group intended merely to. handle calls from B to C this group will probably not handle the extra amount of tratlic that would be imposed by arranging the director to re route the trafiic from A to C so that it goes from A through B and then to C over the i B-to-C trunks. lVhen this is'the case, ar-

group from B to C is large enough to handle extra traffic the calls may be rerouted to C through B when the trunks from A to C are all busy.

In order for the drawings to be understood best, Figs. 1 and 2 should be placed together with Fig. 2 at the right of Fig. 1, and with the interconnecting lines in'alignment, Figs. 3;

andl should be placed with Fig. 4 to the right of Fig. 3 and with Fig. 4 under Fig. 1. Figs. 5 and 6 should be placed under Figs. 3 and 4, respectively.

Fig. 1 shows the trunk circuit TC interposed in the trunk line extending from the line switch bank contacts 24 to the selector S, together with the director selector DS as'sociated with the trunk circuit TC. i

Fig. 2 shows the repeaters R and R accessible from the third and fourth levels, respectively, of the selector S, Fig. 1. The out going trunk associated With the repeater R extends to oflice C, While the outgoing trunk associated with the repeater R extends to ofliceB.

Regarding the director shown in Figs. 8-6, nclusive. flieii ttwn of th l wn in Fig; ficomprises the sequence switches S, and S", together With t-he'relays 201 and 202.

The function of the sequence sw tch S s to distribute the Various series of impulses inrelay 3052,

effect the switch-through operation after the lastdig t is transn' ted. Th P sh f th dire r sh w i i e 4 comprises the Sender, made up of the-sending switch and relays 303 and 550%: 5 to with the; special relay .301 and the r lcase The p rtion o gr" the director shown in 5 con'iprises the oliice register QR, the intern'iediate distributing framejIDF at which the control of the code digits is'eifected, and

the special relays 402 and 40d.

all)

. Then r ien st l s d or shown in Fisticon'iprises the .di 'it registers DR el-fDlif. 4, which are the rigisters that record the subs e n-slice 7 Call from ofic e A'to oflice D. i The layout haying been thus described gen (5 ation vill now be given. For this purpose it Will be assumed that a subscriber in oiiice A dcsiresto converse With a subscriber in oflice D. That being the case, the a-loresaid subscriberin oflice A removes his receiver and dials the number 01 the subscriber in ollice D.

It will be assumed th at, when the subscriber removes his receiver, his line switch selects conductor 6 at armature let.

the trunk line extending through the trunl;

circuit T C to the selector S at the terminals 2, 3, and 4. Accordingly, line relay 9 pulls up over conductors 5 and 7 and over thecalling line and closes at arn' ature 12 acircuit for release relay 10. Release relay l0 encr gizes and places ground upon release trunk At armature 1.6

relay connects test wiper 35 of the director selector DS through arn'iature 30 and its resting contact. to the stepp ng magnet 260i the director selector DS through the local interrupter contacts of the said stepping magnet.

' At armature 15 relay 10 places ground on the loiver terminal of switching relay of the director selector DS, thereby closing a circu t through swltch ng relay 25 and stepping magnet 26- in series.

The further operation Whethercr not thedirector upon which the ip r f h ire e cl c or- S are ste dlly, the detailed description of the oper;

. depends upon I ing is idle. If this director is idle, the test contact on which the test Wiper is standing is ungrounded and the stepping magnet 26 is not operated. Th-at being the case, the circuit through relay 26 is effective, andswitching relay 25 energizes, seizing the director.

. A suming, on t e otherihan r hat th irectorjupon which the ipers .oftil 'e switch DS are standing is busy, Wiper 35 encounters ground potential on the busy tes't' contact, thereby closing circuit for stepping magnet 2.6- -h ar und pct et alr o l pshi short 'reuits relay 25 and prevents it from energizing at this time. Stepping magnet 26 is energized and,"bei ng self-interrupting,

ad anc s t e pers 32-36 t p by step in search of an idle'director.

hen an idle director 18 reached, for example, ,the one shown nrFigs. ;3.6 testwiper gfi'encounters an ungrounded test contact.

wiper 35, thereby making the seized director 7 i busy; at armature 2? relay 25 closes through the special control lead 21; it prepares the impulse circuit at armature 31; and at armas u'res 28 e-ndc29 t connects the conductors 5 and 7 of the selector S to a closed loop in the director over Wipers 33 and 34. This closed loop includes conductors 88and 39, and the resting contact and armature 316 of relay 303 in multiple with contacts 3241 of magnet 305, Accordingly line relay 91 of the selector S pulls up over this closed loop and closes at armature 52 a circuit for release relay 92. Release relay 92 thereupon energizes and at armatures 53, and 54: prepares the switch for operation in the usual manner. I

In the seized director, release relay 302 pulls up overrelcase trunk conductor 10 responsive to the grounding of test vviper 35 of the director-selector DS as above. pointed out. At armature 315 release relay 302 removes ground from release conductor 335 so as to prevent the premature operation of the various release magnets of the director; at armature 812 relay 802 removes ground from the restoring conductor 332 of the sequence switch S; at armature 31 i relay 302 grounds the locking conductor 3841; and at armature 313 it prepares alcircuit "for locking up relay 30.1. i r

The seizure of the director is now complete and, as the impulse circuit is closed through from the trunk'circuit TC to the director. the calling subscriber may now dial the various digits in the desired number. 7

lVhen the calling subscriber manipulates his calling device in. accordance with the first otlice digit, line relay 9 of the trunk circuit TO falls back a corresponding number of times and, each time it falls back it grounds the impulse circuit at armature 13, thereby closing a circuit through the working contact and armature 31, wiper 36, impulse conductor 41, armature 309 of relay 301 and its resting contact conductor 331, series relay 201, sequence switch wiper 209 in its first position, conductor 231, and vertical vmagnet 409 of the office register OR to battery. Vertical magnet 409 operates over the above circuit to raise the wipers of the office register OR step by step until they come to rest opposite the desired level of bank cont-acts.

Relay 201, Fig. 3, is energized in series with the vertical magnet of the oifice register and, being slow acting, maintains its armature 203 attracted throughout the series of impulses. Upon operating, relay 201 closes a circuit for relay 202, whereupon relay 202 pulls up and prepares a circuit for magnet 205 at armature 204.

, Atthe end of the series of impulses, relay 201 falls back and closes a circuit for magnet 205, also opening the circuit of relay 202. A moment'later relay 202 falls back and opens the circuit of magnet 205. By the operation of magnet 205 the Wipers 208 and 209 are advanced one step; iper 209 shifts the impulsing circuit from the vertical magnet conductor 231 to the rotary magnet conductor 232.

Vhen the calling subscriber dials the second ofiice digit, the resulting series of impulses is transmitted by the line relay of the trunk circuit TO, Fig. 1, to the director over the above traced pathas far as wiper 209 of the sequence switch S, Fig. 3, and thence over conductor 232 to rotary magnet 410 of the office register OR. Fig. 5. By the operation of rotary magnet 410 the wipers of the oilice register are rotated step by step and come to rest in engagement with the set of bank contacts individual to the office D. 7 These contacts are indicated on the drawings as Responsive to the above digit, relays 201 and 202 operate as above described to control magnet 205 to advance the wipers of the sequence switch S another step. Viper 209 shifts the operating circuit from the rotary magnet conductor 232 of the oflice register OR to conductor 241 extending to stepping magnet 501 ofthe digit register DR1, Fig. 6. Viper 208 of the sequence switch S grounds wiper 214 of the sequence switch S and also grounds the conductor 233 through the interrupter 210, thereby starting the sending'operation in a manner to be pointed out later.

' Responsive to the dialling of the first subscriber digit in the number, a corresponding number of impulses is transmitted over the impulse circuit as above traced to wiper 209 of the sequence switch S and thence by way of conductor 241, to magnet 501 of the digit register DR''1. Accordingly the Wiper of this'digit register is advanceda number of steps corresponding to the. digit dialled, thereby registeringthe digit. Similarly the digit register DR27 is operated by means of. stepping magnet502, receiving current over conductor 242 when the second subscriber digit is dialled.

Accordingly, responsiveto the thirdand fourth subscriber digits, the digit registers DR-3 and DR-4 are operated by current transmitted over conductors 243 and 244, respectively, and register the said third and fourth subscriber digits. Y c

It is understood, of course, that the sequence switch S moved one contact after each ofthe above series of impulses so as to.dis tribute the impulses to the Various-magnets concerned, and thatthe wipers 208 and 209 advance one more step at the termination of the fourth and last subscriberdigit, and wiper 209 encounters a dead contact. Ac,- cordingly, the wipers of the sequenceswitch S remain in this position-until the direct-or is subsequently freed, at which time the component switches thereof are released. Returning now to the operation'of the sender, which is started upon the connection of ground through the interrupter 210 to the start conductor 233 at the end of the second oflice digit, an impulse of current is transmitted over conductor 233 upon the first subsequent closure of the interrupter 210. This impulse of current is transmitted through armature 210 and its resting contact, and

' resting contact and armature 320, to the stepup wiper 306 encounters a grounded contact with the result that pickup relay 303 pulls up. At armature 316, relay 303 removes the shunt from around the sending contacts 324 of the magnet 305; it grounds the release trunk conductor 40 at armature 317 so as to prevent the premature release of the director in case the calling subscriber-should hang up while a digit is being transmitted; and at armature 318 'it prepares a locking circuit for stop relay 304. i

The shunt has now been removed from around the sending contacts 324 at armature llh and the sendingof impulses, continues until three interruptions havebeen pro duced in the outgoing control :circuit'. When magnet 305 fallsback at the end oitithe third interruption and (closes the outgoing control circuit at the same time advancing the Wipers 306 and 307 one step, wi.per 307 comes :into engagement 7 with the bank contact in which the third impulses stop conductor terminates, thereby closinga circuit for stop relay 304as follows: F =r'om the ground by way of the grounded stop-conductor-control wiper '214 of the sequence switch S,-the first code-digit stop conductor 251, first wiper 421 of the otlice register OR, bank contact 425; the associated driving ratchet wheel preparatory to advancing the wipers213 and 214. At armature 320 relay 304 disconnects magnet 305 from the start wire and connects it through the interrupter contacts 323 to the combined pick-upand restoring wiper 306. Accordingly, magnet 305 is now operated under the control of: wiper 306 and its self-interrupting contacts 323to bring the wipers 306 and 307 around to their normal position. lVhen the normal position is reachedthe operation of magnet 305 ceases and the circuitof the slow acting pick-up relay 303 is opened. This relay, however, does not fall back now on account of the fact that it is slow acting.

Y In the selector S, Fig. 1 line relay 91 falls back responsive to each of the three above mentioned interruptions produced in its circuit by the sending apparatus of the director.

' Uponeach deenergization, line relay 91 com plfetes at armature 52a circuit through armature 54 and. its working contact, series relay 93, series relay94', and vertical magnet 75 to battery. By the operation of vertical magnet 75 the Wipers 6567 are raised step by step until they come to rest opposite the third level of bank contacts, and thevertical test wiper 68 is raised and brought into engagement with the third level test contact (3). Relays 93 and 94 are energized in series with each other and in series with the vertical magnet 75, and, being slow acting, they maintain their respective armatures attracted throughoutthe vertical operation. At armature 55 relay 93 opens a point in the automatic step-- ping circuit of vertical magnet 75. Relay 94,

'upon operating prepares a circuit for stepping relay 96 at armature 56, and at armature '57 opens a point inthe circuit or rotary magnet 77.

Just before the vertical-step ofthe switch shaft is completed, the oif normal contacts 7 9 and 63 close, and contact 63 completes a c'ir- I cuit of the "stepping relay 96 which includes armature 56 and its workingc'ontact, vertical interrupter contacts 74, ofi' normal contacts63, and the rotary interrupter contacts 76. llelay 96 energizes and locks itself at armature 59, and at armature prepares the automatic stepping circuit.

' At the end of the vertical "movement, relays -93and 94'fall back. Relay 94 closes at armature 57 a point in'the circuit'of rotary magnet 77 and at armature 56 opens the initial circuit of stepping relay-96, leaving this relay energized through its locking circuit which includes armature 59 and its working contact. Relay 93, upon falling back, closes at armature 55 a point in the automatic vertical stepping circuit.

From this point the operation depends upon whether the trunk line groupterminating in the third level of bank contacts of the selector S is busy or idle. If the entire group of trunk lines is busy, there is a ground potential on the chain conductor 69 through contactssuch as 106 and 106, Fig. 2, and this ground potential is extendedjthrough the vertical test Wiper 68 to relay 95. Relay 95 is}, accordingly, energized and the stepping circuit is shifted from the rotary magnet 7 7 to the vertical magnet 75 through the series relay 94. That being the case, vertical magnet 7 5 energizes from ground on the grounded releas'etri' nk conductor 6, through the working contact and armature '60, armature 58 and its Working contact, and series relay 94. The slow acting series relay 94 energizes again in series with vertical magnet 75 and closes at armature 56 a shunt around the locking armature 59 and its working contact of the st'eppingrelay 96, and at armature '57 opens a point in the circuit of rotary magnet 77 soas to prevent the premature operation of rotary magnet 7 at the end of the vertical stepping movement. By the operation of verical magnet 7 5, the wipers -67 are raised from their position opposite the third level bank contacts to a. position opposite the fourth level bank contacts. Near the end of its stroke vertical magnet opens the circuit of stepping relay 96 at the interrupter 7 4 whereupon stepping relay 96 falls back and opens the circuit of vertical magnet 75 and theslow acting relay'94 at armature60. hen this occurs, vertical magnet 75 falls back and at contacts 74 completes the circuitof relay 96 from ground through armature 56 and its working contact. Relay 96 accordingly, ener gizes again but it does not close the vertical magnet circuit again at this time on account of the fact that'the vertical test wiper 68 is now in engagement with an ungrounded test lilh contact,namelythe test contact associated with the first set of contacts in the fourth level and, near the end of its stroke, opens the circuit of stepping relay 96 at the interrupter contacts 7 6. When this occurs, relay 96 falls back and opens a further point in its locking circuitat armature 59, and at armature 60 opens-the circuit of rotary magnet 77. R-

tary magnet 7 thereupon falls back and closes its interrupter cont-acts 62 again.

iii

iii

From thispoint the operation depends upon whether the trunk terminating in the first set of bank contacts in the fourth level is busy or idle. If it is idle, the test contact engaged by test wiper 66 isungrounded and switching relay 97 energizes, seizing the trunk. Assuming, however, that the first trunk is busy,

ground is encountered on the test contact thereof-by test wiper 66, short circuiting the switching relay 97 and again energizing stepping relay 86. Relay 96 again completes its locking circuit at armature 59, and at armature again completes the circuit of rotary r magnet 77, whereupon the wipers 67 are advanced another step. 7 This alternate operation of relay 96 and magnet 77 continues as described until an idle trunk is reached, which trunk, it will be assumed is the one comprising conductors 81-83. 4

When this idle trunk is reached, switching relay 97 being'no longer short circuited pulls up in series with stepping relay 96. Stepping relay 96, however, does not operate at this time on account ofthe relatively high resistance of switchingrelay 97. -Upon energizing, switching relay 97 removes ground at armature from the line relay armature 52; it opens the test circuit and prepares the holding circuit at armature 62, thereby grounding the test wiper 66 to make the seized trunk busy immediately; and at armatures 61 and 64 it disconnects conductors 5 and 7 from line relay 91 and extends them 'by way of wipers and 67 and conductors 81 and 83 to the line relay 111 of the repeater R. Relay 111 now energizes over conductors 81 and 83 and closes atarmature 113 a circuit for the release relay 112, which thereupon energizes and grounds the release trunk conductor 82 at armature 115, As a further result of its energization,

relay 111 closes at armature 114 a bridge across the outgoing trunk conductors, whereupon the distant selector S in the office B is prepared for operation in the usual manner.

In the director, the slow acting pick-upre lay 303 falls back after a slight interval responsive to'the returnto its normal position of wiper 306, as above pointed out. At armature 318' relay 303 opens the locking circuit 02 the slow acting stop relay 304, and atarmature 325 it opens the circuit of magnet 211 of the sequence switch S, whereupon the wipers 213 and 214 are advanced one step,

Stop relay 304 falls back after a slight interval and again connects the stepping magnet 305 of the sending switch SEN 'to the start Wire 233 at armature 320." Accordingly, the sccond'codedigit 6 is transmitted in the same manner as the first code'digit 3. In this case the transmission of impulses'continues until the end ofthe sixth interruption in the outgoing control circuit at the sending contacts 324 of magnet 305. At this time the wipers 306 and 307 advance another step and wiper 307 encounters a groundpotential on the bank contacts in which the sixth impulse stop conductor terminates. The circuit for stop relay 304 at this time is-as follows: from ground by way of wiper 214 of the sequence switch S, the second'bank contact, the second code digit stop conductor 252, the second wiper 422 of the oflice register OR, bank contact 426, the associated jumper onthe intermediate distributing frame IDF, the sixth impulse stop conductor, stop wiper 307 of the sending switch SEN, and stop relay 304 to battery. Responsive to'the energizationof stop relay 304 the second code digit 6 is terminated inthesame manner as the first code digit 3 and the wipers'213 and 214 of the switch S are again advanced one step in the manner heretofore described Wiper 214 grounds the third code-digit stop conductor 253. i In the present case twozcode digits are enough. Accordingly, the third and fourth bank contacts in the office register OR asso ciated with the oflice D are'not wired to any of the impulse stop con'du'ctorsbut are instead jumpered over to the skip conductor 417.

'Thatbcing the cas'e'whenthe thirdwiper 42: of the'ofiice register OR is groundedover conductor 253, ground potential istr-ansmitted by way of bank contact 427, and the self-interrupting contacts 212 to the stepping-mag V net 211 of the sequence switclrS. Stepp ng magnet 211 energizes and, being self interrupting, again falls back, thereby advancing wipers 213and-214 another step.- Viper 214 grounds the'fourth code digit stop conductor 254 with the result thata circuit is closed through the fourth wiper 424 of the office register OR, bank contact 428, theassociated IDF jumper, and the skip conductor 417 for stepping magnet 211 again. Accordingly,

the wipers 213 and 214 are automatically advanced another step,'and"wiper 214 shifts the ground potential from the fourth code-digit conductor 254'to the first subscriber-digit stop conductor 261.

y li dire t w is a e m nt -c t:W1

: ener lectsan idle trunk extending to the oiiice D for ezgample the trunk extending to the selectonS g M I tetni ning now to; the director, as the first subscriber-digit stop cond-ntctor 261, which leads to the Wiperof the digit register. DB1

Fig. 6, is now grounded, the nezgt digit. to'be, transmitte d is theffi rst subscriber digit. 7 This digit transmitted; in the hereinhel one described manner and is terminated upon the.

iper; otthe dig it negistenDR-l is standing. Upon the'terinination of-thisdigit, Wipers 21 3; and 21 i of the sequence switch S advance again with the; result that ground potential. is,

shilted; from the first'su-bscriber digit stop condiictor to thesecond' subscriber digit stopcondncton Accordingly, the second-subs scriber (llglt, Which jisregistered, on the digit reg ster Di t-2 1s transmitted in the usual manner. Similarly, the third. and fourth sub-- scriher digits,v which are registered on thedigit 1 egisters-DR-'3-a-nd. Eli- 1' are transj.--

niitted 1n v the hereinbefore described manner.

At the endoi? thetransrnission-ot the fourth subscriber; digit, ,Wipers 213:.and21 1 of the sequence switch SQ are advanced another step with the-resultthatwiper 214i removes ground from the; fourth subscriber-digit step conduc:

ingbranclt 21501 the impulse conductor 331,

' The impulse conductor 331 is openiat this time in-tlie director on account of the fact thatthe Wiper 2090f thesequence sWitchS isstanding;

ontandea'd contacts The impulse circuit is con:-'

nected, at itsorigi-n, however, to the, switching relay 11 oi the. trunkcircuit 11C through armature13 .anditSYworking con-tact of; line relay 9, Accordingly;switchingrelay11 ener[ gizesover the impulse conductor and looks itseli to the grounded release trunk conductor; 6 at] armature 19; it connects the release trunk conductor 6' with the release trunk conductor 6- at armature 18; and at armature and-20 1t disconnects conductors 5: and 7 from grounded,lwuicveQtroni the release trunk S t-he selector'S raises its: Wipers opposite the sixth level nesponsive; 'tothe transmission of theise cond codedigit 6 -z'ation of stop relay s over. the panticularimpulse,stop conductor on which the.

n erfere on w e afi Atarmatu el ne exl -cites I the circuit oiiswitchingrelay 25-otthe idirec; torasele'cton D. yheneuponrelayy 245 falls back, freeing-tliefdirectori a i e to S r e Up n-fell ng ack, re y;- 302gr011nds t me-tutether stQ ng;

I In the directon release. relayfiQifallssb'acls p'on y ti) the remev t e, smi e P9- when frgnirelease-trnnk conductor 40: when.

conductor oi the sequence switch, Si; 7

i -1e hi akes p ce c rcuit sclc edi 'tl1I.O11gl1, '(119612213 the interrupter; con.

1 ee ef r see g; mag et Z ILWi Ihi the sul iha-t. he W pers1213 and; 2M d;

an d he remeinings en o he r nQnme ,-"RQ- t mi t ar a ure relay gteun s the release conductor; 555;;thereby, closing p t z e a c r ui s; hneugh h rar e i r -i 10;:- al: c s the o epcs tion s tc esrc thedireCtor; Eon exainple a-circuit is closed;

h g 01f no'lima cc t t e f to ith n ce e magnet $11 of; theoiiice; register OB; and a circuit is closedthrough ofi' norinal cont-acts 207 for release magnet 296; of the sequence switch. S-,simila r circuits being closed for the release magnets of the digit registers DR 1- DR 1. The: result is that the; van

rious: release magnets energize, and-: the; re-

spectihzcv Wipers are; rest-cued; to; their normal;

positions, the circuits 01% the release magnets being thenlopened atithe respective ofli normal: contact-8., 9 v

In, the oiiice D, the selecton SE is operated opposite the desired level in; accordance with the; tl'a-ll'SllllSSlOni '01" the first subscriber; dig-it whichqwas previously registeredconthe dig-it registerDR-1' Fig; 6;; the hundreds selecu,

tor-seizedghy the selector S is: operatedfinaccordance .withthedigit registeredion the? digit register DR 2 and tIZLl'iSIDlttBCl-3$-l16lffl111b8- tore pointed. out; and theiconnctfoiz switch seized by the hundned selector in use is open;- ated in accordance vWitln the dig" 5, registered- .l/Vlien the call-ingasubscribcrZlicplacjes his receiver at the terminetion of thieiconversa- 7 tion, the; circuit ofl'in-e relay 11 1i oithe repeater R is opened. 7 Line relay 11151. falls,

back andat armature 11A: opens the bridge across. the; outgoing trunk cbnductons-fwith "the result that the connection, extending through the jofiice D to theoiii'ce B; isreleased in the usual manner. At armature 113; relay ll l opens the circuit of-the slow acting re "leaSerelay 112', which deener gi-zesafter: an.

tenva-l and removes ground from vthe: release trunlc conductor 82 atjai-niatnre 1%15 When this occurs, s-witclnn-grela y 9Zo5fitheselctot .S and; switching relay-11 of the trunk circuit TC fell back, kind; the calling lineswitphreleased; in the, usual manner, I Upon thedc energ ization oi relay 97cthe=se1ector S, a

ito the selector S circuit is completedat armature through armatures 52 and 5 L at the off normal contacts T9 for release magnet 78, whereupon release magnet 78 restores the wipers 6567 totheir normal position in the usual manner.

The circuit of release ma net 78 is o ened at oitl' normal contacts 79.

The foregoing examples'erv to illustrate how the calls which are normalli trunked,

there is no ground potential on the chain .con-

ductor 69 with the result that relay is not energized at the end of the vertical. movement. Accordingly, no automatic vertical operation will take place, but, in id, the regular rotary n'uignet circuit is completed right away upon the fallingbacl: oi relays 93 and 94. In this case the selector S selects an idle trunk in the third levclfleading to the office C. For example, the trunk leading Accordingly, when the second code digit is transmit-ted by the 'director as hereinbefore-pointed out, the selec tor S raises its wipers opposite the sixthlevel' and selects an idle trunk extending to the '.':()lll6 D, for example the trunk extending to' the selector S. Call from office A to 0; 506 6.

Assuming now that a calling subscriber in the oflice A desires to converse with a Sll'br,

scriber whose line terminates in ofiice C and that, upon the removal of the receiver at the calling substation, the connection is extended throughto the selector S, as hereinbefore do .v

scribed, and that the director selector DS seizes the d rector shown "121 1912.1.3'A6, the

calling sucscribcr now dials tne oitice LlZgltS assigned to the oiiice C, followed by the four subscriber digitsin the number, with the result that the otlice register OR, brings its wipers 4214 24 into enga ement with the C oiiice bank contacts 429' 2, and that the digit registers DR-1'DR-4 are operated to register tl'lesubscriber digits of the number. V V V It will be noted that the first bank contact 4-29 of the set allocated to the C otiice is across connected on the intermediate distributing frame IDF to the special conductor 455.. Ac cordingly, when the stopconductor-contro-l wiper 214 of the sequence switch S is ground ed at the end of the rotary movement of the oflice register-OR, upon the sequence switch time 404 for the special relay 401. This relay thereupon pulls up and locks itself to the grounded conductor 334 at armature 404, at the same time opening its initial circuit so m to prevent the locking ground potential from remaining permanently on the special cond uctor 455; extends the. special conductor 455 at armature 405 through the jumper 456 110 the third impulse stop conductor to control the sending out of the first code digit 3; and at armature 417 prepares a circuit for the specialcut-otl' relay 301, Fig. 4, which latter circuit is closed only 'in case the selector S, Fig. 1, is'automatically raised to the fourth level responsive to a busy condition of all the third level trunks as will hereinafter ap pear.

From the foregoing it may be seen that as the first code digit stop conductor-251 is now connected through the circuit above traced, including the special conductor 455 and armature 405 and its working contact to the third impulse stop conductor, the first code digit to be transmitted is the code digit 3. lVhen this transmission takes place the selector S, F 1 raises its wipers opposite the third level of contacts-in the manner hereinbefore described. Assuming now that there is at least one idle trunk in the thirdlevel, the vertical test relay 95 of the selector S is not energized at the end of the vertical move ment and the rotary movement commences as soon as relays 93 and 94: fall back. Assuming that the trunk comprising conductors 71--72 is the one selected, the connection is extended thru to the repeater Rupon the energization of switching relay 97 which takes place when the idle trunk is reached. Accordingly, line relay 101 of the repeater R pulls up and closes a bridgeacross theoutgoing trunk conductors at armature 104, with the result that theselcctor S F 1g. 8 is prepared for operation in the usual manner. At armature 103, line relay101 closes a circuit for release relay 102 which thereupon energizes and places ground on the release trunk conductor 72 at arma' ture 105. At armature106, relay 102 closes a point in the chain circuit for supplying ground to the vertical-test chain conductor 69.

In the director, the sequence switch S is advanced one step in the usual manner at the end of the transmission of the first code digit 3, and wiper 214 removes ground from the first code di git stop conductor 251 and extends it instead to the second code digit stop conductor 252. The second code'digit stop conductor 252 is connected through the second wiper 422 of the office register OR, bank contact 430, the associated IDF jumper, special conductor 4-54, armature 403 and its resting contact, and the associated jumper to the skip conductor 417. The result is that the Wipers of the sequence switch S are automatically advanced in the hereinbefore described III in this case as in the one described.

fourth level in response to the condition of all trunks busy on the third level, a circuit is Closed by the fourth level shaft springs which extends as previously traced as far as contact 453, Fig. 5 from which point it now extends through the new jumper between terminals 45S and 452 to battery through the special code control relay 402. 'Relay 402 now pulls up and disconnects conductor 454 from the skip conductor and connects it instead through the working contact of armature 403 to the fourth impulse stop conductor. Accordingly, when the sequence switch S advances responsive to the falling back of the slow acting pick-up relay 303, (which it does in the manner pointed out'hcreinbefore) and places ground on the second code digit conductor 252, the second code digit position is not skipped as in the preceding case, but instead the'fourth impulse stop conductor is ground to predetermine that the next code digit is transmitted, that is, when, after the sending operations have again started, the wiper 307 of-the sending switch SENlands on the bank contact in which the fourth impulse stop conductor terminates. stop relay 304 energizes over the following circuit: from ground by way of the grounded Wiper 214 of the sequence switch S, the second bank con tact, the second code digit stop conductor 252, wiper 422 of the office register OR, bank contact 430, the associated IDF jumper, special conductor 454, armature 403 and its working contact, the associated IDF jumper, the fourth impulse stop conductor, and thence by way of wiper 307 of the sending switch SEN and stop relay 304 to battery. This energization of the stop relay results in the termination of the digit being transmitted. After the usualtime intervals. the sequence switch S is again advanced and shortly thereafter the sending of the next digit commences. In the office B, Fig. 8, the selector S responds to the second code digit 4 to raise its wipers opposite the fourth level and to select an idle trunk therein. For example, the trunk extending to the C office and terminating in the selectoi'S In the director, the next code digit 5 is now transmitted in the manner hereinbefore described as the sequence switch S is now in Instead of this. when the selector S, Fig. l is automatically raised from the third level to the,

tered thousands digit now takes place in the same manner as described hereinbefo're.

Call from ofii'ce A to ofli'ce E.

Considering now the manner in which a call originated in the A office and intended for a subscriber in the E office is handled, it may be seen upon reference to Fig. 8 that the same number of code digits is required in this case as when the C office is called. It will be noted that the only difference between the codes of the C office and the E office is that whereas the final code digit on calls to the C office is the digit 5, the final code digit when the E office is called is the code digit 2. It

will be seen further that since the calls from the A office to the E office are all handled through the C office andthat the thousands selectors in the E office are accessible to the same office selectors S and S to which the call to the office E, the selector S raises its. wipers opposite'the third level of bank contacts and completes the connection to a selector in the C office, such as the selectors,

provided there is an idle trunk in the third level. In this case, it is obvious that the transmission of the next and last code digit'2 completes the call to the E office. However, in

case all the third level trunks are busy, the

selector S in the A office is automatically operated to the fourth level and it selects an idle trunk to the B office, for example, the trunk extending to the selector 8'. In this case, as in the case of a call to the C office, the connection must be denied in case the trunk lines from B to C cannot be used. On 7 the other hand, an extra digit must be introduced to trunk the call from theB to C office in case it is permissible to use the B to C trunk for calls directed to C from A.

It may be seen from the diagram, Figs? and 8, that the office E is more or less an outlying'office. Accordingly, itmay be readily supposed that this is a relatively new office and one in which the traffic is increasing at a fairly rapid rate owing to the building up of the territory which it serves. That being the case, it is desirable to have a ready means for ascertaining the traffic directed to the E office in order that the trunking facilities may be changed from time to time as the traffic conditions change. This situation has been taken care of by providing in the director shown in Figs. 3-6 suitable metering arrangements,

Referring now to Fig. 5, it will he noted that the first bank contact 133 associated with the E oti'ice position or the oliice register OR is cross connected on the intermediate distrib uting frame IDF to the same special conduc tor 455to which the f rst bank contact 429 of the set belonging to the G ofiice is cross connected. Therefore, on calls to the E otiice relay lOl pulls up and ope ates armature 4:17-

just as described hercinbelore on callsto the C office. It will be noted further that the second bank contact 424 of the set belonging to the E oilicc iscross connected on the intermediate distributing frame in the same manner as the second bank contact I or the set belonging to the C otlicc. Accordingly, the second code digit position on calls to the E oliice is skipped or is used. to transmit the extra digit e'necessary to trunk from B to C, subject to the same conditions as described in connection with calls from the A o'tiice to the B otlice.

From the above it maybe seen that the same special arrangements provided to take care or one oiiice may be used to take care or as many oliices as desired that are reached through the first-mentioned ofiice.

It Villl be noted that Flg. 5 shows a meter M. This meter is used to register the numher of calls directed to the otlicer It is for this purpose associated With the special terminals 4A1 and 442; It Will be noted that the third contact 435 in the group assigned to the cities E is jumpered on the intermediate distributing frame IDF to the special terminal 441. Accordingly when the third wiper 423 of the otfice register GR is grounded by the sequence switch S on a call to the E office, the ground potential is extended over conductor 445 to energize the magnet 143 of the meter-M. IV hen magnet 443 energizes it opcrates the associated armature-446 to turn the number-Wheel registering mechanism to register the call, and it also places ground on conductor l l hvrhich is extended to the special terminal H2 and from then by Way or theassociated IDF jumper to thesecond impulse stopconductor so as to transmit the last office digit 2 in the usual manner.

What is claimed is: 1. In a multiofficetelephone system,- a director for transmitting digit combinations to trunk calls to any one of a plurality of offices,

dicate the total number of calls directed to the corresponding otiice, a Wiper on said o'iiice registe and means whereby said Wiper controls the said meter and said sending mechanism. I V

3. In a register sender having separate connections between the register and the senderbanlr for each or several positions or the register, a mete included in one or d connections to indicate the total number of times the sender is controlled from the corresponding setting of the register.

4. In a director, a register, asenderincluding a counting device, contacts in the bank of said register connected to said counting de- Vice, a meter, another contact in said bank connected to said meter, and contacts on said meter tor extending a connection to said counting device.

5. In a multi-oiiicetelephone system, a director in one otlice having a plurality of operative positions, one for each otiice, a meter for indicating the total number of times that the director is. operated to a position corresponding to one of said ofiiceaand means controlled by the meter for transmitting a group of digit impulses;-

6. In a director for automatic telephone systems, an otlice re ister and a digit register for registering a called number, a meter, means dependent upon the setting of the ofiice register for operating the meter to indicate the number of times a given office is called, a sending device, and means con trolled by said meter'tor controlling said sending device. V p In a telephone system, a trunk line, meansior transmitting groups of digit impulses over the trunk line, a meter, means eftective'prior to the transmission of the last of the groups of impulses and dependent upon thevalue of the impulses transmitted for: operating said meter, and means controlled by the meter for transmitting a group of digit impulses." Y

8. In a telephone system. atrunk line,

means for transmitting groups of digit imbearingindividual designations, means for transmitting group designating impulses and line designating impulses over the trunk, a meter', a register, anda circuit through said register for determining the value of the group designatingimpulses and effective prior to the transmission of the'line designating impulses for operating the meter.

5 bearing individual designations, means for transmitting group designating impulses and line designating impulses over the trunk, a meter, mean-s dependent upon the Value of the group designating impulses and effective prior to the transmission of the line desl0 ignating impulses for operating the meter, and means controlled by the meter for transmitting a fixed number of impulses over the trunk.

In witness whereof, I hereunto subscribe my name this 23rd day of May, A. D. 1927.

LEONARD L. RUGGLES. 

